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Vulnerability record · CVE-2021-4133 · published 25 January 2022

CVE-2021-4133: Redhat keycloak incorrect authorization vulnerability

Redhat · Keycloak

A flaw was found in Keycloak in versions from 12.0.0 and before 15.1.1 which allows an attacker with any existing user account to create new default user accounts via the administrative REST API even when new user registration is disabled.

8.8 CVSS 3.1 High EPSS 1.4% · top 29.1% CWE-863 · Incorrect authorization
8.8CVSS 3.1 base score, v2 6.5
1.4%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
8References
17 Jun 2026Last modified by NVD

Description

A flaw was found in Keycloak in versions from 12.0.0 and before 15.1.1 which allows an attacker with any existing user account to create new default user accounts via the administrative REST API even when new user registration is disabled.

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://bugzilla.redhat.com/show_bug.cgi?id=2033602 Issue TrackingThird Party Advisory
https://github.com/keycloak/keycloak/issues/9247 Third Party Advisory
https://github.com/keycloak/keycloak/security/advisories/GHSA-83x4-9cwr-5487 Third Party Advisory
https://www.oracle.com/security-alerts/cpuapr2022.html Not Applicable
https://bugzilla.redhat.com/show_bug.cgi?id=2033602 Issue TrackingThird Party Advisory
https://github.com/keycloak/keycloak/issues/9247 Third Party Advisory
https://github.com/keycloak/keycloak/security/advisories/GHSA-83x4-9cwr-5487 Third Party Advisory
https://www.oracle.com/security-alerts/cpuapr2022.html Not Applicable

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2021-4133), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.